U.S. patent application number 11/574787 was filed with the patent office on 2008-10-02 for hydraulically operated protector for downhole devices.
Invention is credited to Jean-Philippe Bedel, Christophe Rayssiguier.
Application Number | 20080236835 11/574787 |
Document ID | / |
Family ID | 34931377 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080236835 |
Kind Code |
A1 |
Rayssiguier; Christophe ; et
al. |
October 2, 2008 |
Hydraulically Operated Protector For Downhole Devices
Abstract
It is provided a tool and its operating procedure, to protect
any device while lowering into a well, and especially hydraulic
devices such as sensors with expandable arms or inflatable elements
such as packers. The protection is mainly important in the open
hole of highly deviated or horizontal wells, for any device
equipped with external seal element, delicate sensor or articulated
parts. This tool features an automatic sequence controlled by a
single dart or a single ball launched into the running string from
the surface: when the dart or the ball lands on its seat, the
pressure build-up is initially applied to a piston to extract the
device from the protector without exposing it to any differential
pressure, then it is automatically applied to the device itself for
actuation as soon as the device is entirely pulled out of the
protector.
Inventors: |
Rayssiguier; Christophe;
(Melun, FR) ; Bedel; Jean-Philippe; (Scotland,
GB) |
Correspondence
Address: |
SCHLUMBERGER TECHNOLOGY CORPORATION;David Cate
IP DEPT., WELL STIMULATION, 110 SCHLUMBERGER DRIVE, MD1
SUGAR LAND
TX
77478
US
|
Family ID: |
34931377 |
Appl. No.: |
11/574787 |
Filed: |
August 24, 2005 |
PCT Filed: |
August 24, 2005 |
PCT NO: |
PCT/EP05/09234 |
371 Date: |
January 24, 2008 |
Current U.S.
Class: |
166/332.1 |
Current CPC
Class: |
E21B 23/04 20130101;
E21B 17/076 20130101; E21B 17/1085 20130101 |
Class at
Publication: |
166/332.1 |
International
Class: |
E21B 34/14 20060101
E21B034/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 10, 2004 |
EP |
04292174.2 |
Claims
1. A service tool for a hydraulically actuated downhole device
including a tubular sheath for covering at least part of the device
when the device is run into a wellbore; and a piston assembly
disposed in the tubular sheath, abutting the upper extremity of the
device, said assembly including: a hydraulic piston, said piston to
displace the device between an upper position where the sheath
covers at least part of the device and a lower position where the
device is essentially outside the sheath; and said piston including
a tubular body and a dynamic seat translating along said tubular
body means for preventing fluid circulation into the device while
the piston is displacing it and reestablishing it when the device
is outside the sheath.
2. The service tool according to claim 1, further including a
locking device to secure the piston assembly in the upper position
while the service tool is run down the well.
3. The service tool according to claim 2, wherein said locking
device includes shearing pins.
4. The service tool according to claim 1, wherein the tubular body
includes locking means to prevent translation of the dynamic seat
as long as the piston is not in its lower position.
5. The service tool according to claim 4, wherein said locking
means are deactivated when the piston assembly abuts a recess
located in the vicinity of the lower extremity of the tubular
sheath.
6. The service tool according to claim 5, wherein said locking
means includes a sliding sleeve with a groove, said sliding sleeve
in downwards movement with the piston until it abuts the recess and
the dynamic seat includes a ramp housing, at least one ball, said
ball blocking the relative translation of the dynamic seat as long
as the piston is not lowered to a position in which the groove and
the ramp are in communication, allowing the ball to get out of the
way of the dynamic seat.
7. The service tool according to claim 6, wherein the piston
assembly includes at least one key that frees the dynamic seat when
the key is compressed by the recess of the tubular sheath.
8. The service tool according to claim 4, wherein the dynamic seat
is moveable downwards inside the downhole device.
9. The service tool according to claim 4, wherein the dynamic seat
includes at least one fluid flow path and the tubular body includes
at least one bypass slot so that fluid communication is achieved
when the dynamic seat is translated to face the by-pass slots.
10. The service tool according to claim 9, further including means
to disconnect the device from the piston.
11. The service tool according to claim 2, wherein the tubular body
includes locking means to prevent translation of the dynamic seat
as long as the piston is not in its lower position.
12. The service tool according to claim 11, wherein said locking
means are deactivated when the piston assembly abuts a recess
located in the vicinity of the lower extremity of the tubular
sheath.
13. The service tool according to claim 12, wherein said locking
means includes a sliding sleeve with a groove, said sliding sleeve
in downwards movement with the piston until it abuts the recess and
the dynamic seat includes a ramp housing, at least one ball, said
ball blocking the relative translation of the dynamic seat as long
as the piston is not lowered to a position in which the groove and
the ramp are in communication, allowing the ball to get out of the
way of the dynamic seat.
14. The service tool according to claim 13, wherein the piston
assembly includes at least one key that frees the dynamic seat when
the key is compressed by the recess of the tubular sheath.
15. A service tool for a hydraulically actuated downhole device
including a tubular sheath for covering at least part of the device
when the device is run into a wellbore; and a piston assembly
disposed in the tubular sheath, abutting the upper extremity of the
device, said assembly including: a hydraulic piston, said piston to
displace the device between an upper position where the sheath
covers at least part of the device and a lower position where the
device is essentially outside the sheath; and said piston including
a tubular body and a dynamic seat translating along said tubular
body, wherein the dynamic seat is moveable inside the downhole
device; means for preventing fluid circulation into the device
while the piston is displacing it and reestablishing it when the
device is outside the sheath a locking device to secure the piston
assembly in the upper position while the service tool is run down
the well.
16. The service tool according to claim 15, wherein the tubular
body includes locking means to prevent translation of the dynamic
seat as long as the piston is not in its lower position.
17. A service tool for a hydraulically actuated downhole device
including a tubular sheath for covering at least part of the device
when the device is run into a wellbore; and a piston assembly
disposed in the tubular sheath, abutting the upper extremity of the
device, said assembly including: a hydraulic piston, said piston to
displace the device between an upper position where the sheath
covers at least part of the device and a lower position where the
device is essentially outside the sheath; and said piston including
a tubular body and a dynamic seat translating along said tubular
body means for preventing fluid circulation into the device while
the piston is displacing it and reestablishing it when the device
is outside the sheath a locking device to secure the piston
assembly in the upper position while the service tool is run down
the well, wherein the tubular body includes locking means to
prevent translation of the dynamic seat as long as the piston is
not in its lower position.
18. The service tool according to claim 17, wherein said locking
means are deactivated when the piston assembly abuts a recess
located in the vicinity of the lower extremity of the tubular
sheath.
19. The service tool according to claim 18, wherein said locking
means includes a sliding sleeve with a groove, said sliding sleeve
in downwards movement with the piston until it abuts the recess and
the dynamic seat includes a ramp housing, at least one ball, said
ball blocking the relative translation of the dynamic seat as long
as the piston is not lowered to a position in which the groove and
the ramp are in communication, allowing the ball to get out of the
way of the dynamic seat.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of downhole
tools. More particularly the invention relates to servicing
apparatus for completing downhole wells such as hydrocarbon
wells.
BACKGROUND ART
[0002] In the art of well drilling, it is common practice to run
multiple tools, often using conventional setting mechanisms. In
cased wells, tool wearing by the casing is typically limited.
However, in uncased wells, the borehole walls constitute highly
abrasive surfaces that tend to damage the tools, in particular
elements that are in contact with the borehole walls when running
the tools that are typically folded away during placement
operations and/or elements that are deflated such as packer, often
made of rubber or other readily abraded materials.
[0003] Some types of cover sometimes protect the most sensitive
parts of the tools but overall, the tools are left exposed to the
aggressive wellbore environment, for example as in patent U.S. Pat.
No. 6,315,041. This raised issues in particular with the
development of horizontal or highly deviated wells where the tools
may be literally dragged along the borehole. The risks of
deteriorating a tool while handling it at surface should also not
be neglected.
[0004] These issues are of particular concern with a technology
consisting of placing a cement plug using a flexible, expandable
form made for instance of a stretch fabric formed from steel,
rubber, glass fiber, carbon fiber or para-aramid fiber, that holds
the cement in place and thus allows rigorously correct placement.
Since the mesh is necessarily loose to allow deformation, threads
can easily get loose, thereby creating holes through which the
cement slurry will escape.
[0005] Therefore, it would be desirable to provide some protecting
means to tools until their proper placement in the well. It would
also be desirable that the means for operating said protecting
means be fully compatible with the tool operating means, in
particular, does not require any additional power supply.
SUMMARY OF INVENTION
[0006] In a first aspect, the present invention proposes a
protecting assembly consisting of a service tool including a
tubular sheath for covering at least part of the device, for
instance while the device is transferred from the surface down the
hole. Abutting the upper extremity and disposed in the tubular
sheath is a piston assembly that comprises a hydraulic piston with
a tubular body and a dynamic seat translating along the tubular
body. The hydraulic piston displaces the device between an upper
position inside (or at least partly inside) the sheath and an
active position outside the sheath. Means is also provided for
preventing fluid circulation towards the device when the piston
displaced it--and for reestablishing fluid circulation after
extraction of the device out of the sheath.
[0007] In the above definition, the terms upper and lower actually
respectively refer to the position along the borehole nearest and
farthest to the surface (hence upper and lower position in a
vertical well, though the invention is also applicable, and indeed
particularly suitable, to horizontal or highly deviated wells).
[0008] The protecting means of the invention are fully compatible
with hydraulically actuated devices, that is either moved or simply
operated by a pressure build-up of wellbore fluids as this is the
case for instance for a fluid activated packer where the fluid
pressure expands an expandable body having a hollow interior to
engage the inner wall of the casing or of the borehole.
[0009] Since both the protecting assembly and the hydraulic device
are hydraulically actuated, it is crucial to prevent fluid
circulation to the device during the device extraction. However, it
is also important to resume such a circulation after the
extraction. This problem is essentially solved thanks to the
dynamic seat.
[0010] According to a first embodiment of the invention, the
dynamic seat translates all along the device. This embodiment, also
referred as "long-stroke" dynamic seat in the remaining part of the
following description, is applicable when the device inside
diameter is large enough for allowing the seat to travel through
it, until the fluid can actuate the device. Optionally, the device
may include a second seat, larger than the dynamic seat and located
at the upper extremity of the device that can be used to disconnect
the device from the protecting sheath.
[0011] According to another embodiment of the invention, also
referred as "short-stroke" dynamic seat in the remaining part of
the following description, the dynamic seat travels only along a
short distance so that openings of the seats face by-pass slots
provided in the tubular body so that fluid communication is
possible when the seat is in its lower position. This embodiment is
suitable whatever the diameter of the hydraulic device.
[0012] According to a preferred embodiment, the protecting device
of the invention further includes locking means for preventing an
accidental displacement of the dynamic seat, for instance to make
the relative translation of the dynamic seat only possible once the
piston has extracted the device out of the sheath.
[0013] In yet another preferred embodiment, means are provided for
disconnecting the hydraulic device from the piston assembly so that
the piston and the protecting sheath can be retrieved out of the
well and refurbished for another operation.
[0014] The protecting service tool of the invention provides
multiple benefits. The device is perfectly protected during surface
transportation and installation. The system is fully operated by
hydraulic pressure: no movement is required in the running string,
which is especially suitable for horizontal or deviated wells. The
actuation of the system can be controlled from the surface by using
a single ball or dart, which greatly simplifies the operation (no
volume calculation between darts, no need for a dart launcher,
pumping is continuous . . . ).
[0015] The automatic sequence of events simplifies the operation
and it eliminates the risk of human error. Moreover, the operation
can be monitored from the surface by observing a specific pressure
signature. The extraction of the device can be achieved at any
pressure, as the device is not exposed to that pressure. The device
is not exposed to any differential pressure before it is entirely
pulled out of the protector. This is important because a
prematurely actuation could prevent the correct extraction out of
the protector and/or damage the device. Thus the system is
compatible with hydraulic devices such as a bag made of woven
material, an inflatable rubber element, or an articulated arm
operated by pressure.
[0016] Other aspects and advantages of the invention will be
apparent from the following description and the appended
claims.
BRIEF DESCRIPTION OF DRAWINGS
[0017] The invention will now be described in greater detail with
reference to the accompanying drawings, in which:
[0018] FIG. 1 is a schematic view of a protecting means according
to the present invention with a long-stroke dynamic seat;
represented with the tool in storing position (FIG. 1-A) and in
active position outside the protect ting sheath (FIG. 1-B);
[0019] FIG. 2 is a schematic view of a protecting means according
to the present invention with a short-stroke dynamic seat;
represented with the tool in storing position (FIG. 2-A) and in
active position outside the protecting sheath (FIG. 2-B);
[0020] FIG. 3 is a detailed view of the dynamic seat with locking
means including pivoting keys represented in storing position (FIG.
3-A), pivoting (FIG. 3-B) and open to free the dynamic seat (FIG.
3-C);
[0021] FIG. 4 is a schematic view illustrating some key steps of
the operating sequence of the invention with a long-stroke
embodiment;
[0022] FIG. 5 is a detailed view detailed view of the dynamic seat
with a short stroke embodiment. The locking means includes a
combination of balls and grooves, represented in storing position
(FIG. 5-A), pushing out position (FIG. 5-B) and final position
where the device is actuated (FIG. 5-C); and
[0023] FIG. 6 is a schematic view of an automatic valve that
preferably equipped a device protected according to the present
invention in the short stroke embodiment.
DETAILED DESCRIPTION
[0024] The same references will be used to reference the same
elements in the Figures throughout the description.
[0025] FIG. 1 is an illustration of a first embodiment of the
present invention where the dynamic seat moves all along the
protected device. As shown FIG. 1A, a tubular protective sheath 1
is secured, for instance through threading, at the bottom 2 of
tubing, drill pipes, jointed pipes, coil tubing or other string of
pipe known in the art. The dimensions of this sheath 1 are adjusted
to entirely protect the device against shocks during
transportation. Installation though sheaths ensuring only partial
coverage may also be used in some cases. The sheath 1 is typically
made of a strong material such as steel, for instance as a casing
joint.
[0026] A hydraulically operated device 3 is stored inside the
sheath. In this illustrated case, the protective sheath 1 extends
all along the tool but it goes without saying that the invention
may also be carried out with a protecting sheath covering only the
upper part of the device 3.
[0027] To extract the protected device from its envelope,
extracting means are provided. Said extracting means essentially
consists of a piston assembly includes at least one piston seal 4
in contact with the sheath 1 so that the pressure in the running
string can positively move the device out of the envelope; a
connector 5, made of a tubular body; a dynamic seat 6 and seat
locking means 7. In the illustrated case, the locking means 7
includes pivoting keys as it will be further detailed in relation
with FIG. 3. Another seat stop 8 is located at the bottom of the
hydraulically operated device.
[0028] The protective means according to the invention are operated
as follows: the protected device 3 is downloaded into the well in
the stored position. Flow circulation through the protective sheath
1 and the device 3 is allowed. Then, a ball 9 or a dart is pumped
from the surface, lands onto the dynamic seat 6 and closes the flow
path. This causes an increase of the pressure in the running string
and the whole piston assembly is pushed towards the lower extremity
of the protective sheath 3. During that stage, the dynamic seat 6
cannot be pushed out of the tubular body thanks to the seat keys 7.
Once the piston assembly reaches the lower extremity of the sheath,
as schematized FIG. 1B, the locking means 7 are unlocked to free
the dynamic seat 6 that keeps moving along the device now fully
extracted. The dynamic seat ends its course when blocked by the
seat stop 8 so that the pressure can now be applied to the device
itself to actuate it, without requiring an extra ball or dart.
[0029] If the inside diameter of the hydraulically operated device
is not large enough for allowing the dynamic seat to travel through
it, the embodiment schematized FIG. 2 may be used. This embodiment
will be referred to as the short-stroke embodiment since the
dynamic seat travels only the length of the tubular body. As
illustrated FIGS. 2A and 2B, the whole service tool includes a
tubular sheath 1 covering at least part of a downhole-actuated
device 3 and a hydraulic piston to extract the device. The
hydraulic piston includes at least one seal 4, a dynamic seat
displaceable within a connector 5 and locking means 7.
[0030] In the present case, the locking means 7 is made of several
linking elements (balls, keys, collet) secured by a sliding sleeve
33, but it goes without saying that the pivoting keys mentioned
while describing the long-stroke embodiment could also be used, as
the linking elements here described and further detailed in
relation with FIG. 5 could be used in any embodiment.
[0031] The main difference with the later embodiment is the
provision of by-pass slots 10 in the connector 5. The location of
these slots is such that, once the ball or the dart 31 has landed
on the seat, the fluid circulation is blocked as long as the
dynamic seat is blocked by the locking means 7 and the fluid
circulation is reestablished once the device has been entirely
pushed out of the sheath and further progression of the dynamic
seat has been made possible by the actuation of the locking means
7. In that case the bottom of the device must include a valve that
automatically closes as soon as the device moves out of the
envelope. An example of automatic valve that takes advantage of the
device movement to close is described hereafter in relation with
FIG. 6.
[0032] An additional landing seat 11, located on top of the
connector may be optionally provided, to close the flow path again
when a second ball or dart of larger dimension has landed on that
seat, for instance for a surface monitoring of the system
operation. Alternatively, it is also possible to provide a third
position for the dynamic seat corresponding to that monitoring
position.
[0033] An optional connector can be added to the system, so that
the device can stay downhole while the protector is retrieved and
reconditioned. A mechanical connector, such as shear pins, can be
used. Alternatively, a hydraulic connector operated by a second
ball or dart or when the pressure exceeds a given threshold,
provides a convenient way to disconnect without applying tensile
load or any physical movement on the device. Such connectors are
well-known in the art of downhole tools.
[0034] FIG. 3 shows a detail of the piston assembly as used in the
configuration represented FIG. 1 and in reference with FIG. 4,
illustrates the implementation of the long-stroke dynamic seat
embodiment. The piston assembly includes a piston body 5 having its
lower extremity 20 screwed on the protected device 3. The piston
assembly includes lateral stop means 21 and 22 that maintains the
piston assembly centered within the protective sheath 1. In the
initial storing position (FIG. 3-A and step #1 of FIG. 4), the
piston assembly is held in position by shear pins 23 associated
with the upper stop means 22 to prevent unwanted displacement of
the piston assembly until a positive pressure is applied to it.
Other latchable locking device, well known to those skilled in this
art, can be used. A series of seals 4, located between the piston
body 5 and the sheath 1 seal that annulus.
[0035] A dynamic seat 6, with an internal profile 24 to stop a ball
or a dart 31, is positioned inside the piston body 5. To seal the
annulus between the piston body 5 and the dynamic seat 6, a series
of O-ring seals 25 may be provided.
[0036] Several slots 26 have been cut into the piston 5. These
slots form pivots 24 and provide storing spaces for several
pivoting keys 27. In the keys neutral position illustrated FIG. 3A,
the shoulders 28 on the top of the keys are engaged in a groove 29
cut in the dynamic seat outside diameter, so that the seat 6 cannot
translate downward as long as the keys 27 are in neutral position.
That position is obtained by a spring 30, such as a Garter spring
or an O-ring, located in a groove cut in the piston body 5. In this
neutral position, the lower side of the keys is not flush with the
body outside diameter in their extremity.
[0037] When a ball or a dart 31 is pumped down from the surface
through the running string, it lands into the receiver profile 24.
The dart is sealing the receiver inner path. As a consequence, the
fluid cannot be pumped anymore and the pressure starts increasing
on top of the dart, which creates a force pushing the dart and the
receiver downward. The load is transmitted to the keys 27 and to
the pivot point 24 of the piston 5. Consequently the piston
assembly is pushed downward.
[0038] As illustrated FIG. 3-B and in step #2 of FIG. 4, when the
force is high enough, the pins 23 that were securing the piston
assembly inside the protector shear, and the whole internal
assembly (device, lock, body, keys, receiver and dart) is pushed
downward. The device 3 is thus moved outside the protecting sheath
1. At that moment no pressure is applied inside the device, so the
device cannot be actuated. The load to actuate the piston can be
very powerful, as the pressure applies on the full area of the
sheath bore. So the system can work at any deviation, or even in
horizontal wells.
[0039] In step #3 (FIG. 4), once the device is entirely located
outside the protector, the lower extremities of the keys 27 engage
inside a recess 32 provided near the lower extremity of the
protecting sheath 1, which creates a torque and makes the keys 27
pivoting in their grooves. As a consequence, the key shoulders 28
are no longer engaged in the receiver groove 29, and the dynamic
seat is free. On the other hand, the course of the piston body is
blocked by the stop means 21 abutting the recess 32.
[0040] As shown FIG. 3-C, the pressure will now move the dynamic
seat 6 and the dart 31 downward, until they stop against a recess
cut in the Device, in such a position that the pressure will now be
applied to the device 3 to actuate it; for example, an inflatable
packer will inflate or the pumped cement inflates the cement bag as
shown in step #4 of FIG. 4.
[0041] Optionally, as illustrated with step #5 of FIG. 4, the
system includes a hydraulic connector between the device and the
piston assembly. When the pressure rises above a given threshold,
or when a second, larger dart lands inside the connector as
illustrated, the connector is triggered and the device is
disconnected from the protecting assembly, enabling its retrieval
and refurbishing.
[0042] As mentioned before, the locking means that prevent the tail
course of the dynamic seat can be made of pivoting keys as
illustrated FIG. 3. Another alternative illustrated FIG. 5 includes
the use of a series of balls and by-pass slots. This figure also
illustrates details of the short-stroke embodiment where the main
difference with the long-stroke dynamic seat is that the second
position of the dynamic seat is located in front of by-pass slots,
so that the pressure can be applied to the device after a very
short stroke of the seat. This design reduces the risk of being
stuck in the middle of a long stroke, and it is mandatory for any
device with no or insufficient path for the dart.
[0043] The piston assembly includes a tubular body 5 sliding within
a sleeve 33 and a dynamic seat 6. During transport, upper shear
pins 23 prevent displacement of the piston assembly relative to the
protective sheath 1 and lower shear pins 34 prevent displacements
relative to the sleeve 33 until a dart 31 is pumped, lands on the
receiver 24 of the dynamic seat 6 so that the assembly is sealed,
pressure is applied to the full area of the seal and the load on
the whole assembly is high enough to shear the upper pins 23 (FIG.
5-A). At its lower extremity, the dynamic seat includes a ramp 35.
In the storing position illustrated FIG. 5-A, this ramp 35 faces a
window 36 made in the part of the tubular body already engaged in
the sleeve so that it forms housings for several balls 37 wedged
laterally between the sleeve 33 and the ramp 35 and vertically by
the tubular body. The combination of ramps, windows and balls forms
a locking devices that blocks movement of the dynamic seat relative
to the piston body.
[0044] As illustrated FIG. 5B, the whole internal assembly (formed
by the tubular body 5, the dynamic seat and the sleeve) acts as a
piston and it translates inside the protective sheath 1. At that
stage, the pressure above the assembly is not applied to the device
because the dart is sealing the bore of the body 5. Thus the device
cannot be actuated yet.
[0045] When the device is entirely located outside the protector,
the external sleeve 33 stops against the recess 39 at the bottom
extremity of the protector. The inertia of the assembly or the
pressure load will shear the lower pins 34 that were securing the
sleeve 33 on the body 5. Once the pins are sheared, the body 5 can
translate slightly further until its shoulder 40 stops against the
sleeve 33. In that position illustrated FIG. 5-B, the balls 37 are
located in front of a groove 41 cut in the inside diameter of the
sleeve 33.
[0046] The ramp 35 cut in the dynamic seat 6 can now push the balls
37 into the groove 41, freeing the dynamic seat (FIG. 5-B). Thanks
to the pressure load, the dynamic seat 6 and the dart 31 move
downward to the second position (FIG. 5-C). The dart 31 is now
located in front of slots 42 cut in the body 5. That means the dart
fins 43 are still compressed but the fluid can by-pass the dart and
circulate through the slots 42 down to the device 3. So the device
3 will now be actuated. Its actuation can only occur when it was
entirely located outside the protector.
[0047] It is worth noting that the two proposed locking means (keys
or balls and groves) are not sensitive to the possible shocks that
can occur if the dart lands violently.
[0048] According to a preferred embodiment, the device is equipped
with an automatic valve, located that closes when the device starts
moving out. Once the valve is closed, the pressure can raise inside
the device to actuate it. An example of such a valve is illustrated
FIG. 6.
[0049] A valve assembly 50 is secured to the lower extremity of a
device 3 including an internal flow path 51, so that it closes the
lower extremity of the protective sheath 1. The valve assembly
includes a lower bushing 52, pinned at the extremity of the sheath
using shear pins 53 that secure the device within the sheath in the
open position illustrated FIG. 6-A corresponding to the storing
position. Several flowing bushing ports 54 are drilled though the
bushing 52 and they communicate with an annular chamber 55. The
inside diameter of the bushing is a seal bore 56, where a sleeve
57, with ports 58 can slide. The sleeve 57 includes seals 59
located on each side of the sleeve ports 58.
[0050] The sleeve 57 is connected at the lower extremity of the
device flow path 51, so its location inside the bushing bore is
defined by the device itself. The design can accommodate a rather
large tolerance because the ports have an oblong geometry. In the
storing position illustrated FIG. 6-A, the device is retracted
inside the sheath and the sleeve ports are located in front of the
bushing annular chamber, so the valve is open.
[0051] FIG. 6-B corresponds to the beginning of the device
extraction. The sleeve 57 translates through the bushing bore 56
until the device shoulder 60 stops against the bushing extremity
61. At that moment all seals 59 are engaged in the seal bore 56 of
the bushing 52, closing the sleeve ports. In addition, an expanding
ring 62 slightly expands below the bushing, preventing any backward
movement and locking the valve in closed position.
[0052] Once a sufficient load is applied on the piston assembly, as
illustrated FIG. 6-C, the pins 53 that were securing the bushing on
the sheath are sheared, and the bushing can now move out of the
envelope with the device, and the valve stays closed.
[0053] This unique combination of the invention allows free
circulation of the fluid through the device during installation.
Once a dart or a ball lands on the dynamic seat, the device is
hydraulically extracted from the sheath without being exposed to
the pressure and the automatic valve closes the flow path at the
extremity of the device. Then, automatically when the device is
entirely deployed out of the sheath, it is exposed to the hydraulic
pressure that will actuate it. The whole sequence is entirely
automatic for an easy and safe operation, and it can be initiated
from the surface at any moment by pumping down a single dart or
ball.
* * * * *